By: A2Z RX LLC Editorial Team | Medically reviewed by: [A2Z RX LLC], [CREDENTIALS, e.g., PharmD, RPh], [License/State] | Last reviewed: 10/21/2026] Quick Answers: Macrobid Before and After What is Macrobid?A prescription antibiotic (nitrofurantoin) used for uncomplicated bladder infections. How fast does it work?Many people feel better within one to two days; the full course must still be...